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Urinary Tract Infection Treatment

Most uncomplicated UTIs can be treated with oral antibiotics such as trimethoprim, cephalosporins, nitrofurantoin, or a fluoroquinolone (''e.g.'', ciprofloxacin or levofloxacin). Trimethoprim is one widely used antibiotic for UTIs and is usually taken for seven days. It is often recommended that trimethoprim be taken at night to ensure maximal urinary concentrations to increase its effectiveness. Trimethoprim/sulfamethoxazole was previously internationally used (and continues to be used in the U.S. and Canada); the addition of the sulfonamide gave little additional benefit compared to the trimethoprim component alone. However it is responsible for a high incidence of mild allergic reactions and rare but serious complications. A three-day treatment of trimethoprim/sulfamethoxazole or ciprofloxacin is usually all that is needed.

Clinical trials on humans have not shown that cranberry juice and supplements help with the treatment of UTIs, but they have been shown to help with the prevention of symptomatic UTIs due to the anti-adhesion activities of A Type Proanthocyanidin. See more notes on prevention below.

Pyelonephritis

If the patient has symptoms consistent with pyelonephritis, intravenous antibiotics may be indicated. Regimens vary, and include quinolones (e.g. levofloxacin). In the past, they have included aminoglycosides (such as gentamicin) used in combination with a beta-lactam, such as ampicillin or ceftriaxone. These are continued for 48 hours after fever subsides. The patient may then be discharged home on oral antibiotics for a further 5 days.

If the patient makes a poor response to IV antibiotics (marked by persistent fever, worsening renal function), then imaging is indicated to rule out formation of an abscess either within or around the kidney, or the presence of an obstructing lesion such as a stone or tumor.

Children

For simple UTIs children often respond well to a three-day course of antibiotics.

Recurrent UTIs

Patients with recurrent UTIs may need further investigation. This may include ultrasound scans of the kidneys and bladder or intravenous urography (X-rays of the urological system following intravenous injection of iodinated contrast material). If there is no response to treatment, interstitial cystitis may be a possibility.

During cystitis, uropathogenic ''Escherichia coli'' (UPEC) subvert innate defenses by invading superficial umbrella cells and rapidly increasing in numbers to form intracellular bacterial communities (IBCs). By working together, bacteria in biofilms build themselves into structures that are more firmly anchored in infected cells and are more resistant to immune system assaults and antibiotic treatments This is often the cause of chronic Urinary Tract Infections.